Does the S9 Autoset APAP treat centrals? Or just detect?

[ResmedUser]

I recently got switched from a Resmed S8 Autoset APAP, to the new S9 Autoset APAP. My old S8 APAP worked great for three and a half years until it broke back in December. I see this new S9 APAP detects centrals as well as apneas and hypopneas. But...does the S9 APAP treat centrals at all? My new sleep doc told me the S9 ramps up a little tiny bit if it detects centrals, but not much. The Resmed website is vague about it IMO.

I slept my first night on the S9 APAP last night and downloaded my info today using Resmeds Rescan Version 3.11. I got it from my DME even though they told me they were not supposed to give it to me. I put the chip in this afternoon, downloaded the info and found out I had .3 to .5 central apneas last night in addition to a little obstructive apnea. Even though my overall AHI was really low on this machine...1.9. That is a super low AHI for me, typically my AHI runs 4 to 6 on regular APAP.

So....currently my official dx is OSA. After the do the "official" download and see the centrals, will I get a dx of mixed apnea? I do not have a history of heart problems, just hypertension and I am overweight. I take klonopin (sedative) at night.

But again, does the S9 APAP TREAT centrals...at all?

thanks,

Mikey

[Slartybartfast]

Well, neither, really. Resmed says their machine responds to hypopneas, snores, obstructed breathing and obstructive apneas by ramping up the pressure. However, what ResMed is calling a central is perhaps more properly called a non-obstructive apnea, according to page 4 of http://www.devilbissclinicaleducation.c ... nology.pdf

Resmed states that their machines do not attempt to treat what they call central apneas, which may or may not actually be artifacts created by CPAP treatment. Without wiring up your scalp and monitoring your blood oxygen level, there's really no way to tell if it's a true central apnea or just a non-obstructive apnea. Again, the referenced article explains the difference a lot better than I can.

With respect to your last question, according to Resmed, their machines do not attempt to treat "centrals" at all. Which makes sense since if your airway is already open, nothing is achieved by raising the pressure if you are not breathing. So the machine simply waits for you to take your next breath, and continues on. What IS important, though, is that the "central" apnea is recorded and reported so that the clinician is aware of it and can investigate further if desired.

[KatieW]

Slartybarfast, that is a very informative paper by Devilbiss. Thanks for finding and posting it.

[KimberlyM]

I would say that while the S9 doesn't actually treat centrals, CPAP treatment can bring the number of centrals down if they are sleep onset centrals. I had A LOT of centrals in my sleep study (20 per hour), but upon investigation the centrals were sleep onset centrals. When I first used the S9, my AHI was still 17 (13 centrals, 4 obstructives during treatment). As I used the machine, my centrals came down further and further. This morning my AHI per hour was (1 central, .4 obstructives) CPAP treatment has caused me to sleep deeper and not awaken constantly. I also fall asleep faster because the obstructives are not waking me right after I fall asleep, hence less sleep onset centrals. Better sleep leads to less sleep onset centrals. The only way to know if they are due to sleep onset, is to look at the graphs for the clusters when you first start to fall asleep or if you got up to use the restroom, etc.. I have obstructive apnea, not mixed. Had the centrals been not of the sleep onset kind, I am suspect I would have been diagnosed as mixed.

[sdurbin]

Hey Slartybartfast, I am a huge Douglas Adams fan!

The S9 detects whether the event is obstructive or not by "puffing" and I have found that while the puffing is very subtle, it wakes me up enough for me to remember to breathe and I go right back to sleep. I have read somewhere on this forum that everyone has central apneas to some extent throughout the day but I seem to be more aware of mine when I am awake. It is like I forget to breathe.

I have a spine injury and the technician I worked with said that central sleep apnea is common in these cases.

[Janknitz]

I might also add that 0.3 to 0.5 CA is NOTHING to worry about and it doesn't mean you have mixed or complex apnea. If you truly had one of those conditions, it would have shown up on your sleep study as a cause for concern. It's always interesting to see WHEN those CA's occurred. Commonly they are in the first and last hour of sleep--transitional sleep and--if so--may really be artifacts as you start to move around more, rather than actual events.

If the pressure is too high, in some people that can induce centrals. That's why you need that info--it helps to determine ideal pressures for you (didn't I read somewhere that at least one manufacturer's algorithm will reduce pressure if centrals are detected????). Older machines did not distinguish between CA's and OA's, and I think that was some of the confusion when people had increased AHI as the pressure increased. Now that the machine can evaluate your airway, you can see if the increased AHI is due to CA's rather than obstructive events when the pressure is increased.

[Slartybartfast]

FWIW, from the DeVilbiss article and a whole sloughfull of articles someone else [Edit: Restedgal was the one] posted a while back, my impression is that perhaps CAs are over-rated. Seems we should be more concerned with obstructive events.

Katie, glad you liked the article. When I came across it, I felt I had just found a nugget of gold. Well worth keeping and reading over and over.

Sdurbin, Douglas Adams' brilliant writing made sense to me of an increasingly confusing world, and I revere and honor his intellect and memory for it. Postulating that the Earth's population are descended from the useless, cast-off 1/3 of the inhabitants of a doomed alien civilization makes it hard for me to suppress a giggle when, in a meeting, some marketing dweeb presents projected sales figures for a drug product we in R&D haven't even begun to work on.

[jbn3boys]

If you really want to take a lot of time and research centrals, here is an extensive list of links compiled by rested gal
viewtopic.php?t=3025
Maybe the best part for your situation is this:

At another apnea board:
http://www.apneasupport.org/viewtopic.php?p=24677

In a reply titled "Nope" sleepydave (RRT, RPSGT and manager of an accredited sleep center) responds to honda's question:

honda wrote:
"Thanks for the comments, one other question though, do the 4 central apneas have any significance ?"

"None whatsoever.
sleepydave"